Floods by Sri Hari M https://padlet.com/srihari_1433/pbhufafp7v8d Made with a wish on a star en-us 2019-08-17 06:00:47 UTC 2019-08-17 06:55:28 UTC hello@padlet.com How floods are formed? srihari_1433 https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375153421 https://youtu.be/9hQZCiZ21fk]]> 2019-08-17 06:10:54 UTC https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375153421 Recent floods occurs.... srihari_1433 https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375153571 2019-08-17 06:15:43 UTC https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375153571 For other uses, see Flood (disambiguation).Flooding in a streetContemporary picture of the flood that struck the North Sea coast of Germany and Denmark in October 1634.People seeking refuge from flood in Jawa Tengah, Java. ca. 1865–1876.View of flooded New Orleans in the aftermath of Hurricane Katrina"Regular" flooding in Venice, Italy.Flooding of a creek due to heavy monsoonal rain and high tide in Darwin, Northern Territory, Australia.Jeddah Flood, covering King Abdullah Street in Saudi Arabia.Flooding near Key West, Florida, United States from Hurricane Wilma's storm surge in October 2005.Flooding in a street of Natal, Rio Grande do Norte, Brazil in April 2013.Minor flooding in a parking lot off Juniper street Atlanta on Christmas Eve from thunderstorms caused by an El Nino event. The same El Nino caused recorded highs for January in AtlantaFlash flooding caused by heavy rain falling in a short amount of time.Dozens of villages were inundated when rain pushed the rivers of northwestern Bangladesh over their banks in early October 2005. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured the top image of the flooded Ghaghat and Atrai Rivers on October 12, 2005. The deep blue of the rivers is spread across the countryside in the flood image.A flood is an overflow of water that submerges land that is usually dry.[1] In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrology and are of significant concern in agriculture, civil engineering and public health.Flooding may occur as an overflow of water from water bodies, such as a river, lake, or ocean, in which the water overtops or breaks levees, resulting in some of that water escaping its usual boundaries,[2] or it may occur due to an accumulation of rainwater on saturated ground in an areal flood. While the size of a lake or other body of water will vary with seasonal changes in precipitation and snow melt, these changes in size are unlikely to be considered significant unless they flood property or drown domestic animals.Floods can also occur in rivers when the flow rate exceeds the capacity of the river channel, particularly at bends or meanders in the waterway. Floods often cause damage to homes and businesses if they are in the natural flood plains of rivers. While riverine flood damage can be eliminated by moving away from rivers and other bodies of water, people have traditionally lived and worked by rivers because the land is usually flat and fertile and because rivers provide easy travel and access to commerce and industry.Some floods develop slowly, while others can develop in just a few minutes and without visible signs of rain. Additionally, floods can be local, impacting a neighborhood or community, or very large, affecting entire river basins.Contents1 Etymology2 Principal types2.1 Areal2.2 Riverine (Channel)2.3 Estuarine and coastal2.4 Urban flooding2.5 Catastrophic3 Causes3.1 Upslope factors3.2 Downslope factors3.3 Coincidence4 Effects4.1 Primary effects4.2 Secondary and long-term effects4.3 Benefits5 Flood safety planning5.1 Control6 Analysis of flood information6.1 Flood forecasting7 Deadliest floods8 In myth and religion9 See also10 References11 Bibliography12 External links srihari_1433 https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375153708 2019-08-17 06:20:24 UTC https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375153708 Disadvantages of floods srihari_1433 https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375153778 Effects
Primary effects
The primary effects of flooding include loss of life and damage to buildings and other structures, including bridges, sewerage systems, roadways, and canals.

Floods also frequently damage power transmission and sometimes power generation, which then has knock-on effects caused by the loss of power. This includes loss of drinking water treatment and water supply, which may result in loss of drinking water or severe water contamination. It may also cause the loss of sewage disposal facilities. Lack of clean water combined with human sewage in the flood waters raises the risk of waterborne diseases, which can include typhoid, giardia, cryptosporidium, cholera and many other diseases depending upon the location of the flood.

Damage to roads and transport infrastructure may make it difficult to mobilize aid to those affected or to provide emergency health treatment.


Flooding after 1991 Bangladesh cyclone, which killed around 140,000 people.
Flood waters typically inundate farm land, making the land unworkable and preventing crops from being planted or harvested, which can lead to shortages of food both for humans and farm animals. Entire harvests for a country can be lost in extreme flood circumstances. Some tree species may not survive prolonged flooding of their root systems.[16]

Secondary and long-term effects
Economic hardship due to a temporary decline in tourism, rebuilding costs, or food shortages leading to price increases is a common after-effect of severe flooding. The impact on those affected may cause psychological damage to those affected, in particular where deaths, serious injuries and loss of property occur.

Urban flooding can cause chronically wet houses, leading to the growth of indoor mold and resulting in adverse health effects, particularly respiratory symptoms.[17] Urban flooding also has significant economic implications for affected neighborhoods. In the United States, industry experts estimate that wet basements can lower property values by 10–25 percent and are cited among the top reasons for not purchasing a home.[18] According to the U.S. Federal Emergency Management Agency (FEMA), almost 40 percent of small businesses never reopen their doors following a flooding disaster.[19] In the United States, insurance is available against flood damage to both homes and businesses.[20]

Benefits
Floods (in particular more frequent or smaller floods) can also bring many benefits, such as recharging ground water, making soil more fertile and increasing nutrients in some soils. Flood waters provide much needed water resources in arid and semi-arid regions where precipitation can be very unevenly distributed throughout the year and kills pests in the farming land. Freshwater floods particularly play an important role in maintaining ecosystems in river corridors and are a key factor in maintaining floodplain biodiversity.[21] Flooding can spread nutrients to lakes and rivers, which can lead to increased biomass and improved fisheries for a few years.

For some fish species, an inundated floodplain may form a highly suitable location for spawning with few predators and enhanced levels of nutrients or food.[22] Fish, such as the weather fish, make use of floods in order to reach new habitats. Bird populations may also profit from the boost in food production caused by flooding.[23]

Periodic flooding was essential to the well-being of ancient communities along the Tigris-Euphrates Rivers, the Nile River, the Indus River, the Ganges and the Yellow River among others. The viability of hydropower, a renewable source of energy, is also higher in flood prone regions.

Flood safety planning

Aftermath of flooding in Colorado, 2013
In the United States, the National Weather Service gives out the advice Turn Around, Don't Drown" for floods; that is, it recommends that people get out of the area of a flood, rather than trying to cross it. At the most basic level, the best defense against floods is to seek higher ground for high-value uses while balancing the foreseeable risks with the benefits of occupying flood hazard zones.[24]:22–23 Critical community-safety facilities, such as hospitals, emergency-operations centers, and police, fire, and rescue services, should be built in areas least at risk of flooding. Structures, such as bridges, that must unavoidably be in flood hazard areas should be designed to withstand flooding. Areas most at risk for flooding could be put to valuable uses that could be abandoned temporarily as people retreat to safer areas when a flood is imminent.

Planning for flood safety involves many aspects of analysis and engineering, including:

observation of previous and present flood heights and inundated areas,
statistical, hydrologic, and hydraulic model analyses,
mapping inundated areas and flood heights for future flood scenarios,
long-term land use planning and regulation,
engineering design and construction of structures to control or withstand flooding,
intermediate-term monitoring, forecasting, and emergency-response planning, and
short-term monitoring, warning, and response operations.
Each topic presents distinct yet related questions with varying scope and scale in time, space, and the people involved. Attempts to understand and manage the mechanisms at work in floodplains have been made for at least six millennia.[25][page needed]

In the United States, the Association of State Floodplain Managers works to promote education, policies, and activities that mitigate current and future losses, costs, and human suffering caused by flooding and to protect the natural and beneficial functions of floodplains – all without causing adverse impacts.[26] A portfolio of best practice examples for disaster mitigation in the United States is available from the Federal Emergency Management Agency.[27]

Control
Main article: Flood control
In many countries around the world, waterways prone to floods are often carefully managed. Defenses such as detention basins, levees,[28] bunds, reservoirs, and weirs are used to prevent waterways from overflowing their banks. When these defenses fail, emergency measures such as sandbags or portable inflatable tubes are often used to try to stem flooding. Coastal flooding has been addressed in portions of Europe and the Americas with coastal defenses, such as sea walls, beach nourishment, and barrier islands.

In the riparian zone near rivers and streams, erosion control measures can be taken to try to slow down or reverse the natural forces that cause many waterways to meander over long periods of time. Flood controls, such as dams, can be built and maintained over time to try to reduce the occurrence and severity of floods as well. In the United States, the U.S. Army Corps of Engineers maintains a network of such flood control dams.

In areas prone to urban flooding, one solution is the repair and expansion of man-made sewer systems and stormwater infrastructure. Another strategy is to reduce impervious surfaces in streets, parking lots and buildings through natural drainage channels, porous paving, and wetlands (collectively known as green infrastructure or sustainable urban drainage systems (SUDS)). Areas identified as flood-prone can be converted into parks and playgrounds that can tolerate occasional flooding. Ordinances can be adopted to require developers to retain stormwater on site and require buildings to be elevated, protected by floodwalls and levees, or designed to withstand temporary inundation. Property owners can also invest in solutions themselves, such as re-landscaping their property to take the flow of water away from their building and installing rain barrels, sump pumps, and check valved.]]> 2019-08-17 06:22:44 UTC https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375153778 Advantages of floods srihari_1433 https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375153914 *We get fertile soil
*It helps to form mountains
*It helps to fill the water bodies which doesnot have water.
*Floods contribute to the health of ecologically important wetland areas. Healthy wetlands promote healthy water supplies and even affect air quality. Floods inundate wetlands with fresh waste. They also carry and deposit nutrient-rich sediments that support both plant and animal life in wetlands. In addition, flooding adds nutrients to lakes and streams that help support healthy fisheries.]]> 2019-08-17 06:26:41 UTC https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375153914 floods srihari_1433 https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154207 2019-08-17 06:38:28 UTC https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154207 Floods occurs srihari_1433 https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154251 2019-08-17 06:39:29 UTC https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154251 srihari_1433 https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154318 2019-08-17 06:41:49 UTC https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154318 srihari_1433 https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154368 2019-08-17 06:44:03 UTC https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154368 do srihari_1433 https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154601 2019-08-17 06:51:08 UTC https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154601 done by: srihari_1433 https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154602 *Srihari.M
*Karthikeyan.S.E
7C]]> 2019-08-17 06:51:09 UTC https://padlet.com/srihari_1433/pbhufafp7v8d/wish/375154602